1. Field of the Invention
The present invention, in general relates to scuba diving and snorkeling equipment and, more particularly, to swim fins which are used to augment locomotion whilst in the water.
Swim fins and their limitation are, in general, known. When a person attempts to walk forward, either in shallow water or on land with swim fins attached to his feet, the flexible fin portion engages the ground and makes forward travel difficult at best and precarious or even dangerous at worst.
As such it is common practice to walk backwards, either on land or in the water, when swim fins are attached to the feet. This too is difficult at best and dangerous at worst. To overcome this problem, swim fins have been developed which include a pivot in which the fin portion can be pivoted from a forward position into a rearward position, better suited for forward walking.
However, certain prior types of pivoting swim fins have proven to be difficult to either secure in the swimming position or to release from the swimming position to allow for pivoting into the walking position. Furthermore, the latching mechanisms of certain prior types of swim fins have tended to accumulate sand and debris making them unreliable or difficult to use.
Also, certain prior types of swim fins require removal of a portion of the swim fin and then reattachment later. This approach is difficult, takes time, and includes some element of risk inherent with such use. Once a portion of the swim is detached from the rest of the swim fin and prior to successful reattachment thereof there is danger that the detached portion of the swim fin can be lost by either sinking or by being carried away by the waves and current. A swim fin that latches automatically would therefore be safer to use in the water.
Certain prior types of pivotable swim fins include a latching mechanism that is prone to accumulate sand, dirt, silt, and other debris as the person walks forward, dragging the fin portion behind his foot. This extraneous material may even be compacted into the latching mechanism, thus rendering it inoperative.
In addition, other prior types of pivotable swim fins do not include a latch that allows for easy positive release and automatic engagement when the fin is pivoted into the normal position for use. Certain of these designs have proven unreliable over time.
Some of the prior types of pivotable swim fins also require extensive modification to the basic well proven construction of a non-pivotable swim fin, thus increasing bulk and stiffness. Excessive stiffness tends to make such pivotable swim fins less efficient in the water. Excessive bulk also tends to make such pivotable swim fins especially heavy and potentially uncomfortable to wear.
Certain other of the prior types of pivotable swim fins are unusual in shape or appearance thereby making their use less desirable because a wearer is subject to detection by others and possible ridicule for wearing an anomalous design.
Also when people, such as rescue personnel, jump from either an airplane or from a helicopter into the water, previous types of swim fins provide excessive wind resistance and drag. They also catch a great deal of water when contact is made, thus increasing the impact experienced by the person jumping into the water. This is true whether the jump is of short distance or from such a height as to require the use of a parachute.
Typically when jumping into the water from an airplane or helicopter, personnel will not even attach the swim fin to their feet, but rather will fasten it adjacent to their shins or calves so as to minimize resistance when jumping and traveling through the air and especially when landing into the water. Then, once in the water, they must remove the swim fin from about their legs and attach it to their feet.
This is difficult, takes time, and includes some element of risk to both the rescue personnel and to the people being rescued (because the time required to accomplish the rescue is accordingly increased). Once detached from the leg of the rescue person and prior to successful attachment to his foot there is danger here also that the swim fin can be lost and either sink or be carried away by the waves and current.
Accordingly there exists today a need for a swim fin that allows for safe and easy walking in a forward direction, that is quickly and safely adapted for use in the water, that does not require removal of any portion, which is pleasing in appearance, and reliable. Clearly, such an apparatus is a useful and desirable device.
2. Description of Prior Art
Pivotable swim fins are, in general, known. For example, the following patents describe various types of these devices:
U.S. Pat. No. 3,315,286 to Brion, Apr. 25, 1967;
U.S. Pat. No. 4,752,259 to Tackett et al, Jun. 21, 1988;
U.S. Pat. No. 4,767,368 to Ciccotelli, Aug. 30, 1988;
U.S. Pat. No. 5,083,954 to Jacobs, Jan. 28, 1992;
U.S. Pat. No. 5,108,327 to Klein, Apr. 28, 1992;
U.S. Pat. No. 5,292,272 to Grim, Mar. 8, 1994;
U.S. Pat. No. 5,447,457 to Kamitani, Sep. 5, 1995;
U.S. Pat. No. 5,632,662 to Cadorette, May 27, 1997; and
U.S. Pat. No. 5,683,279 to Raasch et al, Nov. 4, 1997.
While the structural arrangements of the above described devices, at first appearance, have similarities with the present invention, they differ in material respects. These differences, which will be described in more detail hereinafter, are essential for the effective use of the invention and which admit of the advantages that are not available with the prior devices.